Refactor Hero class and repository

Models/Hero.cs

@@ -1,10 +1,44 @@
+using System.ComponentModel.DataAnnotations;
+
 namespace tour_of_heroes_api.Models
 {
+    /// <summary>
+    /// Represents a hero in the Tour of Heroes application.
+    /// </summary>
     public class Hero
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Hero"/> class with the specified name and alter ego.
+        /// </summary>
+        /// <param name="Name">The name of the hero.</param>
+        /// <param name="AlterEgo">The alter ego of the hero.</param>
+        public Hero(string Name, string AlterEgo)
+        {
+            this.Name = Name;
+            this.AlterEgo = AlterEgo;
+        }
+
+        /// <summary>
+        /// Gets or sets the ID of the hero.
+        /// </summary>
+        [Key]
         public int Id { get; set; }
+
+        /// <summary>
+        /// Gets or sets the name of the hero.
+        /// </summary>
+        [Required]
         public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or sets the alter ego of the hero.
+        /// </summary>
+        [Required]
         public string AlterEgo { get; set; }
-        public string Description { get; set; }
+
+        /// <summary>
+        /// Gets or sets the description of the hero.
+        /// </summary>
+        public string? Description { get; set; }
     }
 }

interfaces/IHeroRepository.cs

@@ -17,7 +17,7 @@ public interface IHeroRepository
     /// </summary>
     /// <param name="id">The ID of the hero.</param>
     /// <returns>The hero with the specified ID.</returns>
-    Hero GetById(int id);
+    Hero? GetById(int id);
 
     /// <summary>
     /// Adds a new hero.

repositories/HeroRepository.cs

@@ -9,7 +9,7 @@ public class HeroRepository : IHeroRepository
 
     public IEnumerable<Hero> GetAll() => _context.Heroes.ToList();
 
-    public Hero GetById(int id) => _context.Heroes.FirstOrDefault(h => h.Id == id);
+    public Hero? GetById(int id) => _context.Heroes.FirstOrDefault(h => h.Id == id);
 
     public void Add(Hero hero)
     {
@@ -19,7 +19,11 @@ public void Add(Hero hero)
 
     public void Delete(int id)
     {
-        _context.Heroes.Remove(GetById(id));
+        var hero = GetById(id);
+
+        if (hero == null) return;        
+
+        _context.Heroes.Remove(hero);
         _context.SaveChanges();
     }